Math Multitool Calculator

A collection of simple, handy JavaScript math tools that can be implemented anywhere.

Installation

npm install --save math-multitool

In node:

const MMCalculator = require('math-multitool');

In browsers:

<script type="module" src="./path/to/math-multitool.js"></script>

-or-

import MMCalculator from './path/to/math-multitool.js';

Usage

In plain JavaScript, decimal calculations can be inaccurate:

const x = [0.1,0.2];

console.log(x[0] + x[1]);    // Returns 0.30000000000000004
console.log(x[0] * x[1]);    // Returns 0.020000000000000004

Math Multitool provides a class (MMCalculator) with getters and utility methods that allow you to do things like sum, multiply, average, and get the median of arrays of numbers accurately. With MMCalculator, decimal calculations will be accurate up to 15 digits.

Currently, MMCalculator will perform the following actions:

• Sum
• Multiply
• Divide
• Subtract
• Average (mean, median, and mode)
• Get Minimum
• Get Maximum

MMCalculator class

The MMCalculator class is initialized with an array of numbers.

const myArray = [2, 2.5, 5, 5, 4];
const myCalc = new MMCalculator (myArray);

// MMCalculator uses getter syntax to make performing calculations simple:

console.log(myCalc.max);            // Returns 5
console.log(myCalc.min);            // Returns 2

console.log(myCalc.product);        // Returns 500
console.log(myCalc.sum);            // Returns 18.5
console.log(myCalc.mean);           // Returns 3.7
console.log(myCalc.median);         // Returns 4
console.log(myCalc.mode);           // Returns 5

To change the array, set the value of the calculator object to a new array:

myCalc.value = [5, 15, 8.7, 103, 0.05];

MMCalculator utility methods

MMCalculator's utility methods are:

• add(arg1, ...argN)
• subtract(arg1, arg2)
• multiply(arg1, ...argN)
• divide(arg1, arg2)
• fractionalize(value)
• decimalize(numerator, denominator).

Example:

console.log(MMCalculator.add(0.125, 0.20501)) // Returns exactly 0.33001

Note: Fractionalize is designed to return fractions with denominators equal to a power of 10. That is to say, rather than returning a fraction of [1, 2], it will always return a fraction of [5, 10].

Future Plans

I'll add more math functions to math-multitool.js as I can.